At present, the assembly of tubular structures at their nodes is generally carried out by means of two-part collars, gripping the tubes at the level of the node by means of bolts passing through the collars.
There can also be provided a direct mounting between two tubes at a node, by means of a bolt or other assembly elements with gripping by screwing the assembly by means of pressure screws.
Moreover, there is known in the field of exhibition materials, particularly stages, assembly devices in the form of balls having a certain number of blind holes that can each co-act with a tube or the like, said balls being simply placed over the ends of the tubes.
These different assembly devices of known nodes however have a certain number of drawbacks, namely, in the case of collars, permitting the production of nodes having only a reduced number of tubes and, in the case of the use of balls or the like, not permitting securing the ends of the tubes in said balls. Moreover, the provision of collars does not permit obtaining an appearance compatible for example with the production of certain structures, in particular in the field of leisure time or store equipment.
There is also known, from FR-A-2 694 583, an assembly node for tubular structures in the form of two half-shells assembled together by bolting and provided with corresponding recesses and/or holes for the insertion and the blockage of ends of tubular elements. This node assembly permits assembling, on the one hand, the ends of several tubular elements by means of half-shells, the gripping means between the shells serving simultaneously for blocking said ends at the corresponding recesses and, on the other hand, the mounting of the end of other tubular elements perpendicularly to the plane of the first and maintained in position with specific means therefor.
However, this embodiment does not permit obtaining a grip without play of the tubular elements mounted perpendicularly or in another oblique plane relative to the junction plane of the half-shells, such that there remains the possibility of rotation or pivoting relative to the longitudinal axis of said tubular elements.